You are correct all 4 do give off LARGE amounts of energy (joules or kilo-watt hours), but only if your measure of “large” is in comparison to the amount of mass lost.
All four use the same E=mc^2, so yes all for give a Large conversion to energy.

But I’m sure the context of the question refers to power of each process in the amount of energy released in a unit of time (work, watts, joules/sec).
Fission and Fusion converts much more mass much faster than decay does.